Honestly if I had been in the VA quake I might have resisted the WA instinct to duck cover and hold, and simply bend over and kiss my arse goodbye, expecting a blast wave to follow.
I first heard about the quake from a TV in a hallway, CNN said it was centered 85 miles SW of DC and I automatically thought oh boy, there's are nuclear reactors right about there, maybe something catastrophic happened.
Its interesting to me that both of my initial reactions had nothing to do with earthquakes - I think more often of the DC area as a strategic target area for enemies of the US. Didn't realize it also had serious EQs.
Lono -- you are spot-on. No one I've talked to here has said their initial thought was that it was an earthquake. Most said their first instinct was that there had been a construction accident near or at wherever they were at the time.
The next thought was that there had been a terrorist attack. That's the one that was in my mind when I hustled outside. It was out there that I heard speculation of an earthquake and checked the USGS website.
My first thought on the earthquake possibility was that there had been a catastrophic New Madrid quake and like 1811-1812, it was "ringing bells" back east. When I saw on the USGS site that it was Virginia, my geology geekdom kicked in. I'd previously read everything I could find on Virginia/Mid-Atlantic seismicity.
People in cars had a variety of reactions. One friend was on the 14th Street Bridge and did not notice anything. Another was driving in Bethesda and thought something was terribly wrong with his car and put the transmission in neutral thinking that was the problem.
This degree of shaking in DC has not happened in anyone's lifetime so yesterday's quake lacked context for most of us. I grew up in Los Angeles and remember the '71 Sylmar quake (6.5 magnitude) but that happened at 6:00a and woke us up.
9/11 was my context for this event so thoughts went to attack -- massive bomb explosion. Really, on my way outside my mind was processing how large a bomb(s) would be to cause the earth to move in that way and for such a period of time.
Was relieved to discover it was an earthquake.